J/A+A/620/A28ivo://CDS.VizieR/J/A+A/620/A28doi:10.26093/cds/vizier.36200028CDSSasaki M.Haberl F.Henze M.Saeedi S.Williams B.F.Plucinsky P.P.,Hatzidimitriou D.Karampelas A.Sokolovsky K.V.Breitschwerdt D.,de Avillez M.A.Filipovic M.D.Galvin T.Kavanagh P.J.Long K.S.2018-11-30T09:03:59Z2018-11-26T08:08:39ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesx-ray-sourcesWe carried out new observations of two fields in the star-forming northern ring of M31 with XMM-Newton with two exposures of about 100 ks each. A previous XMM-Newton survey of the entire M31 galaxy revealed extended diffuse X-ray emission in these regions. We study the population of X-ray sources in the northern disc of M31 by compiling a complete list of X-ray sources down to a sensitivity limit of ~7x10^34^erg/s (0.5-2.0keV) and improve the identification of the X-ray sources. The major objective of the observing programme was the study of the hot phase of the interstellar medium (ISM) in M31. The analysis of the diffuse emission and the study of the ISM is presented in a separate paper. We analysed the spectral properties of all detected sources using hardness ratios and spectra if the statistics were high enough. We also checked for variability. In order to classify the sources detected in the new deep XMM-Newton observations, we cross-correlated the source list with the source catalogue of a new survey of the northern disc of M31 carried out with the Chandra X-ray Observatory and the Hubble Space Telescope (Panchromatic Hubble Andromeda Treasury, PHAT) as well as with other existing catalogues We detected a total of 389 sources in the two fields of the northern disc ofM31 observed with XMM-Newton.We identified 43 foreground stars and candidates and 50 background sources. Based on the comparison to the results of the Chandra/PHAT survey, we classify 24 hard X-ray sources as new candidates for X-ray binaries (XRBs). In total, we identified 34 X-ray binaries and candidates and 18 supernova remnants (SNRs) and candidates. We studied the spectral properties of the four brightest SNRs and confirmed five new X-ray SNRs. Three of the four SNRs, for which a spectral analysis was performed, show emission mainly below 2 keV, which is consistent with shocked ISM. The spectra of two of them also require an additional component with a higher temperature. The SNR [SPH11] 1535 has a harder spectrum and might suggest that there is a pulsar-wind nebula inside the SNR. For all SNRs in the observed fields, we measured the X-ray flux or calculated upper limits. We also carried out short-term and long-term variability studies of the X-ray sources and found five new sources showing clear variability. In addition, we studied the spectral properties of the transient source SWIFT J004420.1+413702, which shows significant variation in flux over a period of seven months (June 2015 to January 2016) and associated change in absorption. Based on the likely optical counterpart detected in the Chandra/PHAT survey, the source is classified as a low-mass X-ray binary.2018A&A...620A..28Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/620/A28CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/xmm : XMM-Newton Observation Log (XMM-Newton SOC, 2009)J/A+A/373/63 : M31 second ROSAT PSPC survey (Supper+, 2001)J/ApJ/577/738 : M31 Chandra X-ray point sources (Kong+, 2002)J/ApJ/578/114 : Chandra HRC source in M31 (Kaaret, 2002)J/ApJ/609/735 : M31 Chandra X-ray sources (Williams+, 2004)J/ApJ/610/247 : M31 supersoft and quasi-soft X-ray sources (Di Stefano+, 2004)J/ApJ/643/356 : Transient X-ray sources in M31 (Williams+, 2006)J/A+A/451/835 : Properties of X-ray sources in M31/M33 (Hatzidimitriou+, 2006)J/ApJ/681/1464 : X-ray sources near soft gamma repeater in M31 (Ofek+, 2008)J/A+A/480/599 : XMM-Newton survey of M31 centre field (Stiele+, 2008)J/A+A/495/733 : XMM-Newton spectral survey of M31 disc (Shaw+, 2009)J/A+A/534/A55 : Deep XMM-Newton Survey of M31 (Stiele+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/620/A28https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/620/A28http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/620/A28https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/620/A28https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/620/A28http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/620/A28GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/620/A28/tablea1 (Catalogue of sources detected in the XMM-Newton LP of the northern disc of M31)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/620/A28/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/620/A28/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/620/A28/tablea1?GETtext/xml+votable180.050000true10.745962541.52480.0055555555555555566/2623 2666 2709 2752https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/620/A28?format=asciiX-raydefaultJ/A+A/620/A28/tablea3Spectral fit results of M 31 XMM-Newton LP sources which are most likely background sourcesDOFDegrees of freedomstat.fit.dofintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/389] Idenfication numbermeta.id;meta.mainintNameName (JHHMMSS.s+DDMMSS)meta.idcharl_NHGalUpper limit flag on NHGalmeta.code.errorcharNHGalGalactic foreground N_H_1e+21cm**-2phys.columnDensityfloatE_NHGal? Upper error of Galactic foreground N_H_1e+21cm**-2stat.error;stat.maxfloatnullablee_NHGal? Lower error of Galactic foreground N_H_1e+21cm**-2stat.errorfloatnullableNHint? Additional M31 or intrinsic N_H_1e+21cm**-2phys.columnDensityfloatnullableE_NHint? Upper error of additional N_H_1e+21cm**-2stat.error;stat.maxfloatnullablee_NHint? Lower error of additional N_H_1e+21cm**-2stat.errorfloatnullableGammaPhoton indexmeta.code;spect.indexfloatE_GammaUpper error of photon indexstat.error;stat.maxfloate_GammaLower error of photon indexstat.errorfloatredChi2Reduced Chi^2^stat.fit.chi2floatObsObservation ID(s)meta.id;obscharInstInstrument(s)meta.id;instrcharJ/A+A/620/A28/tablea2Spectral fit results of M 31 XMM-Newton LP sources which are most likely located in M 31ObsObservation ID(s)meta.id;obscharInstInstrument(s)meta.id;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/389] Idenfication numbermeta.id;meta.mainintNameName (JHHMMSS.s+DDMMSS)meta.idcharl_NHGalUpper limit flag on NHGalmeta.code.errorcharNHGalGalactic foreground N_H_1e+21cm**-2phys.columnDensityfloatE_NHGal? Upper error of Galactic foreground N_H_1e+21cm**-2stat.error;stat.maxfloatnullablee_NHGal? Lower error of Galactic foreground N_H_1e+21cm**-2stat.errorfloatnullableNHint? Additional M31 or intrinsic N_H_1e+21cm**-2phys.columnDensityfloatnullableE_NHint? Upper error of additional N_H_1e+21cm**-2stat.error;stat.maxfloatnullablee_NHint? Lower error of additional N_H_1e+21cm**-2stat.errorfloatnullableGammaPhoton indexmeta.code;spect.indexfloatE_GammaUpper error of photon indexstat.error;stat.maxfloate_GammaLower error of photon indexstat.errorfloatredChi2Reduced Chi^2^stat.fit.chi2floatDOFDegrees of freedomstat.fit.dofintJ/A+A/620/A28/tablea4Variability for Field 1 (OBS1 vs. OBS2)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/389] Identification numbermeta.id;meta.mainintRate1Count rate in OBS1ct/sphot.count;em.X-raydoubleRate2Count rate in OBS2ct/sphot.count;em.X-raydoubleRateMeanMean count ratect/sphot.count;em.X-raydoubleDRateCount rate differencect/sarith.rate;phot.count;arith.diffdoublee_Rate1Count rate error in OBS1ct/sstat.errordoublee_Rate2Count rate error in OBS2ct/sstat.errordoubleVarVariability%src.var;arith.ratiointSigniSignificancestat.fit.goodnessfloatfVar[yes no] Variable ?meta.codecharJ/A+A/620/A28/tablea5Variability for Field 2 (OBS3 vs. OBS4)VarVariability%src.var;arith.ratiointrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/389] Identification numbermeta.id;meta.mainintRate1Count rate in OBS1ct/sphot.count;em.X-raydoubleRate2Count rate in OBS2ct/sphot.count;em.X-raydoubleRateMeanMean count ratect/sphot.count;em.X-raydoubleDRateCount rate differencect/sarith.rate;phot.count;arith.diffdoublee_Rate1Count rate error in OBS1ct/sstat.errordoublee_Rate2Count rate error in OBS2ct/sstat.errordoubleSigniSignificancestat.fit.goodnessfloatfVar[yes no] Variable ?meta.codecharJ/A+A/620/A28/tablea6Sources, which have only been detected once even though they were observed twicerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/389] Identification numbermeta.id;meta.mainintNameName (JHHMMSS.s+DDMMSS)meta.idcharObsIDObservation IDmeta.id;obscharJ/A+A/620/A28/tablea1Catalogue of sources detected in the XMM-Newton LP of the northern disc of M31ClassClassification (2)src.classcharNotesNotes (3)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintmoreindicates spectral fit results and/or variability in other tablesmeta.ref.urlcharID[1/389] Sequential identification numbermeta.id;meta.mainintprimaryRAJ2000Rigth ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainePosPosition errorarcsecstat.error;posfloatChandra[y] Whether a counterpart exists in Chandra catalogue (Williams et al., 2018ApJS..239...13W)meta.codecharDetMLSource detection likelihoodstat.likelihooddoubleCtsCountsctphot.count;em.X-raydoublee_Ctsrms uncertainty on Countsctstat.errorfloatCRateCount ratect/sphot.count;em.X-raydoubleHR1? Hardness ratio 1, HR1=(B2-B1/(B2+B1) (1)phot.flux;arith.ratiofloatnullablee_HR1? rms uncertainty on HR1stat.errorfloatnullableHR2? Hardness ratio 2, HR2=(B3-B2/(B3+B2) (1)phot.flux;arith.ratiofloatnullablee_HR2? rms uncertainty on HR2stat.errorfloatnullableHR3? Hardness ratio 3, HR3=(B4-B3/(B4+B3) (1)phot.flux;arith.ratiofloatnullablee_HR3? rms uncertainty on HR3stat.errorfloatnullableHR4? Hardness ratio 4, HR4=(B5-B4/(B5+B4) (1)phot.flux;arith.ratiofloatnullablee_HR4? rms uncertainty on HR4stat.errorfloatnullable[SPH11]? Entry in SPH11 catalogue (Stiele et al. 2011, Cat. J/A+A/534/A55) [SPH2011] NNNN in Simbadmeta.idintnullable